Office-based Vergence Accommodative Therapy Research Articles

Convergence Insufficiency Neuro-Mechanism Adult Population Study: Phoria Adaptation Results

PurposeThe purpose of this study was to compare changes in phoria adaptation between young adult binocularly normal controls (BNCs) and participants with symptomatic convergence insufficiency (CI), who were randomized to either office-based vergence accommodative therapy (OBVAT) or office-based placebo therapy (OBPT).MethodsIn the double-masked randomized clinical trial, 50 BNC and 50 CI participants were randomized to the following therapeutic interventions: OBVAT or OBPT with home reinforcement for 12 one-hour office sessions. A 6∆ base-out and 6∆ base-in phoria adaptation experiment at near (40 cm) was conducted using the flashed Maddox rod technique at baseline and at outcome. Measurements included the rate and the magnitude of phoria adaptation.ResultsAt baseline, BNC and CI participants had significantly different rates and magnitudes of base-in and base-out phoria adaptation (P < 0.001). When comparing the outcome to baseline measurements, significant main effect differences in longitudinal measurements were observed for the magnitude and the rate of phoria adaptation for both base-out and base-in experiments (P < 0.05). For the magnitude and rate of phoria adaptation, post hoc analyses using paired t-tests revealed that the CI group administered the OBVAT intervention exhibited a significant increase in the magnitude and rate of phoria adaptation compared to baseline for both base-in and base-out phoria adaptation (P < 0.01) but not for those administered OBPT.ConclusionsPhoria adaptation is significantly different at baseline between those with normal binocular vision and symptomatic CI participants. OBVAT significantly improves the rate and magnitude of both base-out and base-in phoria adaptation at near compared to OBPT. Results have clinical implications for new therapeutic interventions.

Interventions for convergence insufficiency: a network meta-analysis.

Interventions for convergence insufficiency: a network meta-analysis.

The Convergence Insufficiency Neuro-mechanism in Adult Population Study (CINAPS) Randomized Clinical Trial: Design, Methods, and Clinical Data

ABSTRACTPurpose: To describe the design and methodology of the Convergence Insufficiency Neuro-mechanism in Adult Population Study (CINAPS), the first randomized clinical trial (RCT) studying young adults with symptomatic convergence insufficiency (CI) using a combination of traditional clinical tests, objective eye movement recordings, and functional brain activities as outcome measures.Methods: In this double-masked RCT, binocularly normal controls (BNC) (N = 50) and CI patients (N = 50) are randomized into office-based vergence/accommodative therapy (OBVAT) or office-based placebo therapy (OBPT). Outcome measures included clinical signs and symptoms, phoria adaptation, forced fixation disparity curves, binocular rivalry, vergence and saccadic objective eye movements, and task-induced functional brain activities. This study is registered on ClinicalTrials.gov NCT03593031.Results: No significant baseline differences are observed between the BNC (p > .4) or CI (p > .3) participants assigned to OBVAT or OBPT for age, near point of convergence (NPC), positive fusional vergence (PFV), phoria at distance and near, amplitude of accommodation, or the Convergence Insufficiency Symptom Survey (CISS). Significant differences are observed between the CI and BNC cohorts at baseline measurements for NPC, PFV, difference in phoria from far to near, amplitude of accommodation, and CISS (p < .001). For the CI patients, 26% had a comorbidity of accommodation insufficiency, and 16% self-reported ADHD.Conclusion: Features of the study design include the following: standardized diagnostic and office-based therapeutic intervention, placebo treatment arm, masked clinical outcome examinations, objective eye movement recordings, functional imaging, phoria adaptation, fixation disparity curves and binocular rivalry measurements.

Clinical and Functional Imaging Changes Induced from Vision Therapy in Patients with Convergence Insufficiency.

Office-Based Vergence/Accommodative Therapy (OBVAT) is an effective treatment for convergence insufficiency (CI) and remediates symptoms in about 75% of patients. Hence, the study of CI patients can serve as a systems-level model to understand the neural mechanisms evoked from rehabilitation. Symptomatic young adult CI patients (N=25) participated in 12 hours of OBVAT and were compared to 25 binocularly normal controls (BNC) using unpaired t-tests. CI patients have significantly lower near point of convergence and positive fusional vergence and were more symptomatic compared to BNC (p<; 0.0001). Using paired t-tests, significant differences (p<; 0.0001) were observed between CI patients' baseline and post-OBVAT measurements where the near point of convergence decreased, positive fusional vergence increased, and the results from the Convergence Insufficiency Symptom Survey (CISS) decreased. Using paired t-tests, the mean beta weights of the functional activity significantly increased for the frontal eye fields (p<; 0.01) and the oculomotor vermis (p<; 0.05) for CI patients post-OBVAT compared to baseline measurements. These data demonstrate that OBVAT increases functional activity within the brain and improves clinical function and visual symptoms in CI patients.

Objective Assessment of Disparity Vergence after Treatment of Symptomatic Convergence Insufficiency in Children.

SIGNIFICANCEThis first report of the use of objective measures of disparity vergence as outcome measures for symptomatic convergence insufficiency in children provides additional information that is not accessible with clinical tests. The study results also demonstrate that objective measures of vergence could be used in future randomized clinical trials of binocular vision disorders with children.PURPOSEThis study was designed to evaluate changes in objective measures of disparity vergence after office-based vergence/accommodative therapy (OBVAT) for convergence insufficiency in children 12 to 17 years old.METHODSIn this prospective trial, we recruited 10 participants with normal binocular vision and 12 with convergence insufficiency. All participants with convergence insufficiency were treated with 12 weeks of OBVAT. The primary outcome measure was average peak velocity for 4° symmetrical convergence steps. Other objective outcome measures of disparity vergence included time to peak velocity, latency, and accuracy. Changes in clinical measures (near point of convergence, positive fusional vergence at near) and symptoms were evaluated.RESULTSThere was a statistically significant increase in peak velocity and more accurate response amplitude to 4° symmetrical convergence step stimuli after OBVAT compared with baseline measurements. Near point of convergence, positive fusional vergence, and symptoms also statistically significantly improved after OBVAT. Ten of the 12 participants met clinical success criteria.CONCLUSIONSIn this prospective study on the treatment of symptomatic convergence insufficiency in children in which both clinical and objective eye movement measurements were used to evaluate the results of treatment, significant changes were found in symptoms and both clinical and objective measures of disparity vergence after completion of OBVAT in children with symptomatic convergence insufficiency.

Imaging of Convergence Insufficiency Treatment Effects (ICITE) Pilot Study: Design and Methods

Background: The blood-oxygen-level-dependent (BOLD) signal from functional magnetic resonance imaging (fMRI) identifies brain activation during specific tasks.1,2 This paper describes the design and methodology of the Imaging of Convergence Insufficiency Treatment Effects (ICITE) Study, a two-phase study comparing BOLD activations during vergence eye movements in symptomatic convergence insufficiency (CI) subjects (1) to those with normal binocular vision (NBV) and (2) after office-based vergence/accommodative therapy (OBVAT) versus office-based placebo therapy (OBPT). Methods: Young adults, 18 to 30 years, with NBV or symptomatic CI (near exophoria at least 4Δ [prism diopters] greater than at distance, receded near point of convergence [NPC], and insufficient positive fusional vergence [PFV]) were enrolled. During fMRI scanning, subjects were instructed to fuse a random-dot stereogram stimulus with vergence demands ranging from -3Δ to +25Δ. CI subjects were then randomized to 12 weeks of OBVAT or OBPT. Vision and fMRI examination at outcome were performed by a masked examiner. BOLD signal at baseline was compared between NBV and CI patients. Later, the BOLD response at baseline was compared to that following vision therapy for those with CI. Conclusion: The imaging results are expected to advance understanding of neurological mechanisms of CI and the effects of therapy on the vergence system, which in turn may guide development of future research that could lead to new treatment strategies.

Behavioral and Emotional Problems Associated With Convergence Insufficiency in Children

Objective: This study investigated behavioral and emotional characteristics of children with convergence insufficiency (CI), before and after treatment with office-based vergence accommodative therapy (OBVAT). Method: Parents of 44 children ages 9 to 17 years with symptomatic CI completed the Conners 3 ADHD Index and the Child Behavior Checklist (CBCL) before and after OBVAT. Pre-treatment scores were compared with normative data and post-treatment scores were compared with baseline using the Wilcoxon sign rank test. Results: Following OBVAT, CI children showed a significant mean improvement (p < .0001, effect size of 0.58) on the Conners 3 ADHD Index with the largest changes occurring in the 23 children who scored the highest at baseline. On the CBCL, anxious/depressed, somatic, and internalizing problems improved significantly (p < .001, effect sizes of −0.36, −1.15, and −0.67, respectively). Conclusion: In an open trial, attention and internalizing problems improved significantly following treatment for CI.

Convergence Insufficiency Treatment Trial – Attention and Reading Trial (CITT-ART): Design and Methods

To describe the design and methodology of the Convergence Insufficiency Treatment Trial: Attention and Reading Trial (CITT-ART), the first randomized clinical trial evaluating the effect of vision therapy on reading and attention in school-age children with symptomatic convergence insufficiency (CI). CITT-ART is a multicenter, placebo-controlled, randomized clinical trial of 324 children ages 9 to 14 years in grades 3 to 8 with symptomatic CI. Participants are randomized to 16 weeks of office-based vergence/accommodative therapy (OBVAT) or placebo therapy (OBPT), both supplemented with home therapy. The primary outcome measure is the change in the Wechsler Individual Achievement Test-Version 3 (WIAT-III) reading comprehension subtest score. Secondary outcome measures are changes in attention as measured by the Strengths and Weaknesses of Attention (SWAN) as reported by parents and teachers, tests of binocular visual function, and other measures of reading and attention. The long-term effects of treatment are assessed 1 year after treatment completion. All analyses will test the null hypothesis of no difference in outcomes between the two treatment groups. The study is entering its second year of recruitment. The final results will contribute to a better understanding of the relationship between the treatment of symptomatic CI and its effect on reading and attention. The study will provide an evidence base to help parents, eye professionals, educators, and other health care providers make informed decisions as they care for children with CI and reading and attention problems. Results may also generate additional hypothesis and guide the development of other scientific investigations of the relationships between visual disorders and other developmental disorders in children.

Long-Term Effectiveness of Treatments for Symptomatic Convergence Insufficiency in Children

To assess the long-term stability of improvements in symptoms and signs in 9- to 17-year-old children enrolled in the Convergence Insufficiency Treatment Trial who were asymptomatic after treatment for convergence insufficiency. Seventy-nine patients who were asymptomatic after a 12-week therapy program for convergence insufficiency were followed for 1 year [33/60 in office-based vergence/accommodative therapy (OBVAT), 18/54 in home-based pencil push-ups (HBPP), 12/57 in home-based computer vergence/accommodative therapy and pencil push-ups (HBCVAT+), and 16/54 in office-based placebo therapy (OBPT)]. Symptoms and clinical signs were measured 6 months and 1 year after completion of the 12-week therapy program. The primary outcome measure was the mean change on the Convergence Insufficiency Symptom Survey (CISS). Secondary outcome measures were near point of convergence, positive fusional vergence at near, and proportions of patients who remained asymptomatic or who were classified as successful or improved based on a composite measure of CISS, near point of convergence, and positive fusional vergence. One-year follow-up visit completion rate was 89% with no significant differences between groups (p = 0.26). There were no significant changes in the CISS in any treatment group during the 1-year follow-up. The percentage who remained asymptomatic in each group was 84.4% (27/32) for OBVAT, 66.7% (10/15) for HBPP, 80% (8/10) for HBCVAT+, and 76.9% (10/13) for OBPT. The percentage who remained either successful or improved 1-year posttreatment was 87.5% (28/32) for OBVAT, 66.6% (10/15) for HBPP, 80% (8/10) for HBCVAT+, and 69.3% (9/13) for OBPT. Most children aged 9 to 17 years who were asymptomatic after a 12-week treatment program of OBVAT for convergence insufficiency maintained their improvements in symptoms and signs for at least 1 year after discontinuing treatment. Although the sample sizes for the home-based and placebo groups were small, our data suggest that a similar outcome can be expected for children who were asymptomatic after treatment with HBPP or HBCVAT+.